Search results for "Fuzzy logic"
showing 10 items of 470 documents
Criticality in the Network with Imprecise Activity Times
2002
A review of the results obtained in the area of fuzzy network analysis is presented. The main approaches to the concept of criticality in a network with fuzzy activity times are described and classified. Against the background of this review some new results, obtained by the authors recently, are presented. The paper is an extended version of the work presented in IPMU'2000 (see [8]).
Fuzzy technique for microcalcifications clustering in digital mammograms
2012
Abstract Background Mammography has established itself as the most efficient technique for the identification of the pathological breast lesions. Among the various types of lesions, microcalcifications are the most difficult to identify since they are quite small (0.1-1.0 mm) and often poorly contrasted against an images background. Within this context, the Computer Aided Detection (CAD) systems could turn out to be very useful in breast cancer control. Methods In this paper we present a potentially powerful microcalcifications cluster enhancement method applicable to digital mammograms. The segmentation phase employs a form filter, obtained from LoG filter, to overcome the dependence from …
A Fuzzy Inference Expert System to Support the Decision of Deploying a Military Naval Unit to a Mission
2009
Naval military units are complex systems required to operate in fixed time frames in offshore tasks where maintenance operations are drastically limited. A failure during a mission is a critical event that can drastically influence the mission success. The decision of switching a unit to a mission hence requires complex judgments involving information about the health status of machineries and the environmental conditions. The present procedure aims to support the decision about switching a unit to a mission considering the vagueness and uncertainty of information by means of fuzzy theory and emulates the decision process of a human expert by means of a rule-based inference engine. A numeri…
A fuzzy decision support tool for demand forecasting
2007
In this paper we present a decision support forecasting system to work with univariate time series based on the generalized exponential smoothing (Holt-Winters) approach. It is conceived as an integrated tool which has been implemented in Visual Basic. For improving the accuracy of the automatic forecasting it uses an optimization-based scheme which unifies the stages of estimation of the parameters and selects the best method using a fuzzy multicriteria approach. The elements of the set of local minima of the non-linear programming problems allow us to build the membership functions of the conflicting objectives. A set of real data is analyzed to show the performance of our forecasting too…
Integrating resolution—like procedures with Lukasiewicz implication
1993
We discuss some conceptual and technical problems raised by the attempt of integrating resolution-like procedures with the use of Lukukasiewicz implication Min{1, 1 – [a] + [b]} in an environment of approximate reasoning modelled by fuzzy logics.
An advanced control strategy for biological nutrient removal in continuous systems based on pH and ORP sensors
2012
[EN] A fuzzy logic-based control system that uses low-cost sensors for controlling and optimizing the biological nitrogen removal in continuous systems has been developed. The novelty of this control system is the use of several pH, ORP, and dissolved oxygen (DO) sensors instead of on-line nitrogen sensors/analyzers. The nitrogen control system was developed and implemented in a UCT pilot plant fed with wastewater from a full-scale plant. The developed nitrification controller allows the effluent ammonium concentration to be maintained below the effluent criteria discharge with the minimum energy consumption. The denitrification process controller allows the energy consumption derived from …
PIRACY REVISITED: EXPLORING MUSIC USERS IN THE AGE OF TECHNOLOGY DEPENDENCY
2019
This paper empirically investigates and characterizes users of recorded music, both downloaders and purchasers. To this end we analyse the role of the variables defining the different segments of music users. In doing so, we have considered two main traits influencing the use of music. First, objective variables such as demographics, music consumption habits, music genres and technology. Second, subjective variables such as motives and attitudes towards piracy. Using data from a personal survey, subsequent latent class and fuzzy analyses show that while the former characteristics are relevant in those getting music for free from the Internet, the latter don´t pay any special part, contrary …
An Heuristic Approach for the Training Dataset Selection in Fingerprint Classification Tasks
2015
Fingerprint classification is a key issue in automatic fingerprint identification systems. It aims to reduce the item search time within the fingerprint database without affecting the accuracy rate. In this paper an heuristic approach using only the directional image information for the training dataset selection in fingerprint classification tasks is described. The method combines a Fuzzy C-Means clustering method and a Naive Bayes Classifier and it is composed of three modules: the first module builds the working datasets, the second module extracts the training images dataset and, finally, the third module classifies fingerprint images in four classes. Unlike literature approaches using …
Fuzzy Boundaries in Discourse Studies : Theoretical, Methodological, and Lexico-Grammatical Fuzziness
2019
This book focuses on the multifarious aspects of ‘fuzzy boundaries’ in the field of discourse studies, a field that is marked by complex boundary work and a great degree of fuzziness regarding theoretical frameworks, methodologies, and the use of linguistic categories. Discourse studies is characterised by a variety of theoretical frameworks and disciplinary fields, research methodologies, and lexico-grammatical categories. The contributions in this book explore some of the nuances and implications of the fuzzy boundaries in these areas, resulting in a wide-reaching volume which will be of interest to students and scholars of discourse studies in fields including sociology, linguistics, int…
Degree of monotonicity in aggregation process
2010
In this paper we introduce a fuzzy order relation notion in the description of aggregation process. Namely, we use the fuzzy order relation to define the degree of monotonicity, which is equal to 1 for a monotone function with respect to a crisp order relation. In that case, integration of fuzzy order relation allows us to generalize the notion of monotonicity and we try to investigate the benefits of using fuzzy relations instead of a crisp relation. Further we illustrate this definition by examples and study the properties of aggregation functions which have a certain degree of monotonicity.